I believe you have been working with Ron Strobl. He contacted me about this situation.
I encouraged him to get the airplane approved with the existing tailwheel as it had been approved with a "337." Unless you can find USABLE parts convert back to stock, you will spend a small fortune to recondition and replace worn out parts. The last time I had a piston shaft ground and hard chromed back to size, it cost $450. Chrome Craft in Sacramento rejected two tailwheel yokes as being unrepairable for hard chroming.
Converting to steerable configuration will be a challenge with the fuselage covered. If you go non-steerable, full swivel, you'd better have a fine set of brakes. 'Cause if you don't, you'll be a windmill the next decent crosswind. I know....because I have one Bellanca set up that way.
Dan